Comparator gauge



June 12,'1945.. y P. B. slRvENr COMPARATORGAUGE 2 Sheets-Sheet- 2 Filed Sept. '29, 1943 t broken away.

`Patented June 12, 1945 UNITED STATES PATENT g OFFICE amasar CoMPARA'roR GAGE- Philip Botaya Sirvent, Toronto, Ontario, Qanada Application September 29, 1943, Serial No. 504,227 l (Clics- 1148) Y' 12 Claims.

This invention relates to gauges, particularly to comparator gauges for checking inside diameters or bores of small objects. f

'g The purpose ofthe inventionis to devise a gauge which will be handy, accurate, and cheap and easy to make.r Afurther purpose is't devise a vgauge which will support as well as gauge the object. A still further purpose is to provide means for supporting the object which can be accurately positioned relative to the gauge. f

These and other purposes are achieved by means of the construction hereinafter described by way of example, and illustrated inv the annexed drawings, in which Figure 1 is a plan view of the gauge, `partly Figure 2 a longitudinal sectionof'the gauge on thefline 2-2 in Figure 1; u

Figure 3 a vertical section on the line 3-3 in Figure 2;

Figure 4 a side elevation of the gauge on a reduced scale showing the supporting platform in alowered position in full lines and in a raised position in `dotted lines; n

Figure 5 a side elevation of the adjusting key;

Aand

Figure 6 a cross section on an enlarged scale on the line 66 in Figure 1. l

' In the drawings like numerals Aof., reference indicate corresponding parts in the different figures. The gauge is mounted in the `frame I which is substantially L-shaped in cross section and which enclosesthegmain operating parts of the gauge'. Two"calipers or measuring fingers 2 extend upwardlyand substantially parallel and through a slot in the top of the frame I, one of said measuring fingers being provided with a vsingle ball the object 46 which is beingcheckedrand the platform` 3 is mounted on a post41 which is vertically adjustable in a manner hereinafter rde-r scribed. e I

The measuring fingers 2, 2 areturned outwardly at about an angle of 45 at theirvlower ends and fit into bosses 3, 3 on drums 4, Alwhich are se cured to drums 5,` 5 having flanges 6, yrwhichl ex` tend around the drums for about one half of their periphery and tangentiallyY outwardly and upwardly therefrom, bearings 6% 6a beinginserted inthe tangential portion of the saidi'lanfgesr, 6, said bearings engaging a ball B (see Figure 2);

The tangentialportions of the flanges 6, Aare substantially at right angles to oneanother and on. a plane parallel to the axis' ofl the outturned lower ends of the measuringarms `2, 2, and the bearings 1, I engage the surface of the ball B at points Iapproximately 45 apart, which position will vary somewhat as will hereinafter appear.

YThe flanges, 6 are provided with bosses 1, 'I to which,l are secured arms 88 Ywhich in turn are 'secured to bosses 9, 9 on lsleeves I0, I0 which are rotatably mounted on stub shafts II, II securedv to brackets I2, I2 which extend out from yet() the frame l.- The sleeves I 0, I0 areheldon the shafts I I, I I by means of what are vcommonly `called circlip locks I3, I3 that is to ysay circular range, such means comprising a bolt I4 extending y through the drum 4 and screwingjinto the drum 5, said bolt having a head IM engaging the outer surfaceV ofthe'drum 4 Aand a countersunk multisided recess I4b (see Figure 6). To adjust the position of the measuring'fingers f2 relative tothe armsl 8, the key I5 is inserted through openings I6 .inv the frame I (see 'Figure 4), andv into the recess I4b andv turned to loosen the bolt I4, so that thei'lngers 2 can be moved relative to the arm 8 to desired positions, and then` the bolt tightened up and the key removed,

The measuring fingers 2 are supported and'normally pressedeso that they tend to spread apart bymeans of the pin I1 which is slidably mounted in a bracket I8 and is provided with a head Ila against which a coil spring I9, which surrounds the pin, bearsatone end, the other end of the spring bearing against the bracket vI 8. The head Ila of the pin Il is provided with a recess to receive theball bearing B. The bracketl extends outwardly from the frame I. The lower end of the pinis, provided with a projection I'Ib having a roundedfend adapted to engage the sloping surface 20 of the pivoted arm 2| which suppbrtsthe The arm 2l is pivoted to screw `23 which passes through a collar 24 and screws into abushing in the bracket I8.

A coil spring 25 is'se'cured to the armv 2| and to the supporting web of the bracket I8 tothe left of the crew 23 in Figure 2, exerting a pull on the arm which pulls the sloping plate 20 into contact with the rounded end I1b of the pin |1. A raising and lowering of the pin |1 will thus tend to cause the arm 2| and hence the indieating finger 22 to swing from side to side according to the movement of the pin I1. Inasmuch as the length of the arm to the right of the pivot screw 23 is much shorter than the length of the -arm and indicating finger to the left of said screw, the movement as shown on the indicating finger which is provided with a pointer 22a,

is magnified very considerably so that move-` ment o f the pin over a very small fraction of an inch will be clearly shown by the pointer ,22s. The ratio of movement of the pointer 22 to the contacts surfaces 2e, 2a of the measuring arms .2 is approximately 150 to 1 in the construction illustrated. The indicating finger 22 issbstan-l tially Lshaped and extends upin the frame to a point `beneath the opening 26 which may be covered by a sheet of transparent material such as glass.` Mounted Ion knobs 28 and "29 which slide in a slot 21 in the frame I are two measur-` ing pointers 30-and 3| which can be set as lherein-V after described, to indicate the outside limits of movement of the indicating pointer 22E.

To retain the arms 8, 8 in position during ad-l justment as hereinafter described, shafts 32, 32

the indicating pointer 22a `is approximately centrally located in the opening 26, The knobs 33, 33 lare then tightened upholding the` arms 8, in this position. The bolts wI4 arethen loosened by means of the key I 5 so that the arms 2, 2 may be swung relatively to one another. An object 46 of correct orvmean diameter, such as-a bushing, shown in dotted lines in Figure 2 is placed on the platform 5 with the ends of the measuring fingers 2, 2 within the bore of the obiect and bearing against the sides thereof, The bolts I4, yI4 -may then be tightened andthe knobs 33, 33 loosened. Then an obiect having the maximum permitted diameter is placed over the fingers 2, 2. The indicating 'oointer'22a will swing to one side of the opening 26 andthe measuring pointer 3| moved to a position opposite it. After this has been done another sample object 43 having the minimum permitted diameter is placed over the measuring ngeis 2, 2 and this presses .the said fingers together causing the pin 1 to be pushed down to engagement with the sloping part 20 thus swinging the indica-ting finger 22i and thus the pointer 22e. in the opposite direction. The pointer 3U is thenl placed opposite the pointer 22e. Thereafter, `various objects are tested by being placed over the measuring fingers or calipers 2, and if the indicating pointer 22" swings past either the measuring pointer 30er 3| in either directionthe diameter of the object being checked will be known tovbe beyod the permitted tolerance. I l

It will be seen that ythe gauge is automatically self-compensating for wear on the engaging surfaces 2L or the `bearings 1 and 8. When contact surfaces have become worn, it is necessary only to reset the measuring fingers in the same manner as they were originally set. This may be I done as often as desired if the gauge is being used to check identical bores in quantities.

An'important feature of this invention lies in the fact that integral with the device is an adjustable supporting platform 3, already mentioned. It is important that this platform be perfectly steady and free from motion at all times, and alsothat it be accurately adjustable, withmearis for holding itin anyfdesired adjusted position.

The platform which is provided with a longitiidinal central slot for movement of the measurihg ig'rs 2, 2 is supported from one side by means of a post 41 (see Figures 3. and 4). This post passes 'clown into the frame and is vertically slidable in bearing members which are formed of a fixed part 35 and a movable part 36 which are hinged together along one side by` means ofhinee members 36 and35a and a bolt 31passing through said hinge members from -top to bottom. A pluralityof transverse grooves 38, 38, v38, 38 `are provideduin the bearing members and Q-.shaped spring `clips 39,351,391, 39, in said g'roovesupress theparts `together to rmly embrace Vthe post 41. Preferably three or more bearing surfaces 401are inset in thebearing members 35, S36 and .engage the post 41.

Each lbearingmember has an outwardly ex"4 tending fiange` 35h and 36h on its free edge and the screw 42| passes through the-flange 3|5D and is screwed into the flange 35| intermediate theends thereof. shoulder liliA bears on the flange 33b to ciamp'the anges togetherlwhenthe screw is tightened up. The shaft of the screw 4| passes outthrougha hole in the `frame I and ahandie 42 is provided for turning thescrew. By turn-v ing thehandle to the right, `the two .bearing members 35 and 36 are clamped together vso firmly that the post 41 cannot slide vertically between them. By ,loosening the screw, vertical adjustment of the'postma? be obtained ,although the 'spring clips 39 will maintain the bearings in close contact withthe post at all times.

P'refrabli below the post 41 and between the bearing members 35 and 36 is mounted .a compression spring 43 whichlbears against the bottom of l,the'post ,41 and tiids to force it upwardly. This ooiita'cts the weight `of the host .41 and the platform 3 and provides a buffer. Atable shook ring 44 surrounds the post 41 above the frame l. y

To peven't twisting of the post 41, pins 4'5, 45

are s'rd inv 'said post extending outwardly at rightanglsthreto and into the space between the flanges 35b and 36|. It will thus be seen that I have provided a simple 'ionsti'uction of `comparator gauge and supporting table therefor which Ywill give accurate corhrative measurements over 'a wide range.

By alibratig the indicating opening 23 actual measuiementsmay be obtained. The 'gauge inustratc is' intended to measure variations or as little ag .0001" in holes of from .7500 to 7.000" in diameter. The device is particularly adapted for use at lthe machine, where production parts which are not 'entirely free from ou may be checked without damgi' the gauge. The three point ct'at will chec'l' the `diaz'netei' of any part of the tore', and will detect out of round, and such rgulaities as front taper, back tapenfbellmouth, and barrel shape.,

It is thought that the construction and use of th initioi will be' apparent from the 'above from each other; arms pivoted atr one endon description of the various'` parts and their purpose. It is to be understood that the formof my invention herewith shown and described, is to be taken as` a preferred example of the same, and that various changes in the shape, size and arrangement of parts may be resorted to, without departing from the spirit of my invention, or the scope of the subjoined claims.

What I claim as my invention is: 1. In a gauge, the combinationof a frame; at least two measuring fingers having surface at their outer ends for contacting the object to be measured, atv least one of said measuring fingers being swingable to and from the other finger; an arm pivoted at one end vto the frame and extending at an angle to the said swingalole measuring finger, the inner end of said finger being secured to the other end of the arm; means for adjusting the angle between the measuring finger and the arm; an indicating finger; and means operated by the swinging movement ofthe measuring finger for moving the indicating nger.

2. In a gauge, the combination of a frame; at least two measuring fingers having surfaces at their outer ends for contacting the object to be measured, at least one of said measuring ngers being swingable to and from the other finger; an arm pivoted at one end to the frame and extending at an angle to the said swingable measuring finger, the` inner end of said nger being secured to the Aother end of the arm; meansfor adjusting the angle between the measuring finger and the arm; a pin mounted on the frame for longitudinal sliding movement, said pinv being movable in one direction by .the swinging movement of the measuring finger; means urging the pin in the other direction; and an indicating finger swingably mounted on the frame, said pin being adapted to engage said finger to swing the same.

3. In a gauge, the combination of a frame; at least two measuring fingers having'surfaces at their outer ends for contacting the object to be measured, at least one of said measuring fingers being swingable to and from the other finger; an arm pivoted at one end to the frameand extending at an angle to the said swingable measuring finger, the inner endof said finger being secured to the other end of the arm; means for adjusting the angle between the measuring finger and the arm; a pin mounted on the frame for longitudinal sliding movement; a bearing on said arm'engaging a bearing onl one end of said pin, wherebyk swinging movement of the arm will move the pin in one direction; a spring urging ther pin in the other direction; and an indicating finger movable by the pin.

4. In a gauge, the combination of a frame; at least two measuring fingers having surfaces at their outer ends for contacting the object to be measured, said fingers being swingable to and from each other; arms pivcted at one end on the frame and extending at an angle t`o the swingable measuring finger, the inner ends of the measuring ngers being secured to the other ends of the arms; a pin mounted on the framevfor longitudinal sliding movement, the ends of said arms remote fromv their pivot points bearing against an .end of the pin; a spring tending to move said pin to lift the arms and spread the measuring fingers; and an indicating finger operated by the movement of the pin.

5. In a gauge, the combination of a frame; at least two measuring fingers having surfaces at their outer ends for contacting the object to be measured, said fingers being swingable to`and the frame and extending at an 'angle to the swingable measuring finger, the inner ends of the measuring fingers being secured to the other ends of the arms; means for adjusting the angles between the fingers and the arms; a pin mounted on the frame for longitudinal sliding movement,

the ends of said arms remote from their pivot points bearing against an end of the pin; a spring tendingto move said pin to lift the arms and spread the measuring fingers; and an indicating finger operated by the movement of the pin.

6. In avgauge, the combination of a frame; at

least two measuring fingers having surfaces at their outer ends4 for contacting the object to be measured, at least one of said measuring fingers being swingable to and from the other nger; an arm pivoted at one end to the `frame and extending at an angle to the said swingable measuring finger, the inner end of said finger being secured to the other end of the arm; means for adjusting the angle between the measuring finger and the arm; a pin mounted on the frame for longitudinal sliding movement, said pin being movable in one direction by the swinging movement of the measuring finger; means urging the pin in the other direction; and an indicating finger swingably mounted on the frame; and a sloping surface on one end of the indicating finger engaged by. the pin, whereby longitudinal movement of the pin will cause swinging movement of the indicating finger.

7. In a gauge, the combination of a frame; at least two measuring fingers having surfaces at their outer ends for contacting the object to be;

measured; a platform for supporting the object to be measured; a post for supporting the platform in the desired position relative to the measuring fingers; bearings in which'the post'is vertically movable, said bearings being secured to the frame and formed in two parts which are spring pressed together to maintain the bearings in close contact with the post; and means for releasably securing the post in various vertical positions.

8. In a gauge, the combination of a frame; at leastv two measuring fingers having surfaces at their outer. ends forV contacting the object to be measured; a platform for supporting the object to be measured; a vertically movable post for supporting the platform in the desired position 'relative to the measuring fingers; hinged members mounted on the frame having bearing surfaces for the post; and spring means tending to close the hinged members against the post.

9. In a gauge, the combination of a frame; at least two measuring fingers having surfaces at their outer ends for contacting the object to be measured; a platform for supporting the object to be measured; a vertically movable post for supporting the platform in the desired positioni relative to the measuring fingers; hinged mem-- supporting the platform in the desired position relative to the measuring fingers; a member mounted on the frame havinga bearing surface` for the post; another similar bearing member complementary to the first bearing member; a spring clip extending around the bearing members and tending to close them against the post; and means for Clamping the members in Contact with the post to secure the post in position.

11. In a gauge, the combination of a frame; at least two measuring ngers having surfaces at theirl outer ends for contacting the object to be measured; a platform for supporting the object to be measured; a vertically movable post for supporting the platform in the desired position relative to the measuring ngers; means for releasably securing the post in various vertical positions; and a spring tending to force the post upward to a predetermined position-of maximum height.

12. In a gauge,l the combination of a frame; vat least two measuring fingers having surfaces at their outer ends `for contacting the object to be measured; a platform for supporting the object to be measured; a vertically movable post for supporting the platform in the desired position relative to the measuring fingers; hinged members mounted on the frame having bearing surfaces for the post; spring means tending to close the hinged members against the post; a longitudiga] slot between said hinged members; and a pin extending out from the post and into said slot to prevent rotation of the post.

PHILIP BOTAYA SIRVENT. 

